I connect my laptop to my TV to watch movies, when I connect the cable my laptop screen goes black. How do I set it so that it stays on and not go to black?
Usually you hit the function key and the corresponding F# key which adjusts your output settings. Most laptops default to only outputting to an external monitor and don't show anything on the built-in LCD as a way of saving power. Both can be turned on simultaneously, you just have to use the Function (Fn)+ F# key.